diff --git a/src/shared/conf-parser.c b/src/shared/conf-parser.c
index 5a5a3c76133..d33ee8a9b0f 100644
--- a/src/shared/conf-parser.c
+++ b/src/shared/conf-parser.c
@@ -1005,7 +1005,7 @@ int config_parse_bool(
         }
 
         *b = k;
-        return 0;
+        return 1; /* set */
 }
 
 int config_parse_id128(
@@ -1453,7 +1453,7 @@ int config_parse_ifname(
 
         if (isempty(rvalue)) {
                 *s = mfree(*s);
-                return 0;
+                return 1;
         }
 
         if (!ifname_valid(rvalue)) {
@@ -1465,7 +1465,7 @@ int config_parse_ifname(
         if (r < 0)
                 return log_oom();
 
-        return 0;
+        return 1;
 }
 
 int config_parse_ifnames(
diff --git a/src/shared/conf-parser.h b/src/shared/conf-parser.h
index b73039cc5c8..94f81a3bd63 100644
--- a/src/shared/conf-parser.h
+++ b/src/shared/conf-parser.h
@@ -320,7 +320,7 @@ typedef enum ConfigParseStringFlags {
                 }                                                       \
                                                                         \
                 *i = r;                                                 \
-                return 0;                                               \
+                return 1;                                               \
         }
 
 #define DEFINE_CONFIG_PARSE_PTR(function, parser, type, msg)            \
@@ -337,7 +337,7 @@ typedef enum ConfigParseStringFlags {
                         log_syntax(unit, LOG_WARNING, filename, line, r, \
                                    msg ", ignoring: %s", rvalue);       \
                                                                         \
-                return 0;                                               \
+                return 1;                                               \
         }
 
 #define DEFINE_CONFIG_PARSE_ENUM_FULL(function, from_string, type, msg) \
@@ -357,7 +357,7 @@ typedef enum ConfigParseStringFlags {
                 }                                                       \
                                                                         \
                 *i = x;                                                 \
-                return 0;                                               \
+                return 1;                                               \
         }
 
 #define DEFINE_CONFIG_PARSE_ENUM(function, name, type, msg)             \
@@ -374,7 +374,7 @@ typedef enum ConfigParseStringFlags {
                                                                         \
                 if (isempty(rvalue)) {                                  \
                         *i = default_value;                             \
-                        return 0;                                       \
+                        return 1;                                       \
                 }                                                       \
                                                                         \
                 x = name##_from_string(rvalue);                         \
@@ -385,7 +385,7 @@ typedef enum ConfigParseStringFlags {
                 }                                                       \
                                                                         \
                 *i = x;                                                 \
-                return 0;                                               \
+                return 1;                                               \
         }
 
 #define DEFINE_CONFIG_PARSE_ENUMV(function, name, type, invalid, msg)          \
@@ -448,7 +448,8 @@ typedef enum ConfigParseStringFlags {
                         *(xs + i) = invalid;                                   \
                 }                                                              \
                                                                                \
-                return free_and_replace(*enums, xs);                           \
+                free_and_replace(*enums, xs);                                  \
+                return 1;                                                      \
         }
 
 int config_parse_unsigned_bounded(